Adapters to extend light bulb sockets (“extenders”) are broadly commercially available. However, there are some conditions under which a shortened (smaller bulb displacement) extender is required, such as within a recessed light bulb socket having a glass cover. Extenders that are currently available are not short enough for such particular applications.
There are also adapters for light bulb sockets that allow the control of the intensity of a light bulb. For these types of adapters, a shortened adapter is very desirable since it minimizes the need to change the lamp assembly to incorporate the adapter. Examples include adapters used in a recessed lamp assembly in a ceiling fixture having a glass cover, or used in a table lamp having a harp that holds a shade for which the harp is too short to accommodate the adapter plus the light bulb.
In many versions of adapters, the electronic circuitry used to control a light bulb is incorporated within the adapter, in some configurations within the insulator that surrounds the female part of the adapter. Versions of these adapters are commercially available such as those manufactured by Lutron Electronics, Inc., and can incorporate, for example, switches, photocells, and motion sensors, together with their related electronic circuitry. The problem with these adapters is that the incorporation of the electronic circuitry within the adapter significantly increases the length of the adapter.